Calculate and display the total value of all the items in the array. PROBLEM
- I tried this using a for loop but i'm stuck.... do i create an int for totalValue in the loop as above? i want to get the total of all the items in the array, across 6 objects of 3 types, how do i access a specific variable in that way and get the total??

Call the depreciate method for each item in the array followed by the display details method and note the change in values.
-havn't got this far yet but i assume i'll have a problem. i could just create 3 differant methods in my parent class, one for sub class, eg vehicleDepr() etc, and then call them in the test class, but surely there's a more efficient way to this?

Calculate and display the total value of all the items in the array. PROBLEM
- I tried this using a for loop but i'm stuck.... do i create an int for totalValue in the loop as above? i want to get the total of all the items in the array, across 6 objects of 3 types, how do i access a specific variable in that way and get the total??

You want to sum up in the loop. Anything declared in the loop will be redeclared each time round, so declaring the totalValue in the loop won't work. You need to declare it before going into the loop.

As for getting the value of an Asset, is there a method you could use? Once you have that, then you can just add it to totalValue.

I was told to create a method, depreciate(), that would depractiate the value of double value by given amounts (can be seen in last post). Because of these differing amounts of depreciation, should I create the method in the parent class and use the super. function, or give each sub-class its own method?

Once i have this sorted, how do we call the depreciate method in the test class? and how do we do so when the variable double value is instantiated in a polymorphic array? Do i have to do it for each object individually or can i use a loop?

Yep.
Single method in the parent, which uses a single depreciation percentage attribute in the parent...but that value is set in the constructor of the child classes. So Electronics sets it to 20%, Vehicles to 15% etc.

You'll call depreciate() as you did in the first code snippet you gave two posts up.

An excellent example of inheritance: those classes have a parent class (Asset) and if that parent class also has a depreciate() method the other three classes inherit that method; any of those objects are Asset objects (the extend from that class) so you can call that method on them.